hygger Advanced LED Aquarium Light with Timer, 24/7 Lighting Cycle & DIY Mode, Full Spectrum Fish Tank Light for 36-42 in Freshwater Planted Tank

hygger HG-978 Operating Instructions ("translated")I love this product. I got a smaller version for my 10G tank a year ago, and used that on my 20G"tall" tank as well. This larger one does more, and that's great! You have options. The bad news is, the instructions are somewhat difficult to understand. Like many things made in different parts of the world, sometimes the English instructions need some study to figure out what they really mean. It happens, and doesn't make it any less of a great product, IMO. So, after some study and experimentation, I was able to condense the basics of this light.There are three ways to use it.The first is to simply turn it on, select a color (it has a bunch), set the intensity level, and turn it off when you want to. Basically a "manual" light. One feature here... you can select a "Color Changing Loop" when you pick a color, and it will cycle through all the colors like one of those old Christmas tree back lights , if you remember those... Anyway...The second way to use it is to set a Timer. This light has a 6, 10, or 12 hour Timer setting. It will be "ON" for the selected amount of time from the time you set the Timer. There will be a 15-minute ramp up and ramp down in intensity at the beginning and end of the time selected. So, you select the color, the intensity, and the amount of "ON" time you want, starting NOW, and there it is. Using the light this way, I'd use a 12-hour cycle @ 75% intensity and shutting down about an hour or two after sunset, so I'd have to set the timer around 9AM this time of year to do that, and fiddle with it a few times a year to account for day length.Finally, there is a 24/7 preprogrammed setting. You have no control over the color or intensity or anything else other than figuring out the instructions! The instructions have to do with time. With this automatic setting, the goal is to have it finish at 22:30 or 10:30PM, according to the manual. Now, you only need to do this once... but what you need to do is look at the clock on the wall NOW, and select the starting point either closest to what your local time is right now, or one to "fool" the system into finishing earlier or later than 10:30. The time selections are 0800, 1000, 1200, 1500(3PM), 1800(6PM), and 2200(10PM). The idea is that if you are setting this light up and it's around noon, select the 1200 setting and it will now cycle without any further input. Off and into the night light at 10:30, and beginning the dawn routine at 8AM. That's it! I set mine at 0700 and selected the 8AM setting. The lights are running in night mode at 9:30PM rather than 10:30PM. So, you can offset or "fool" the system to shift the cycle around the clock a bit. A couple of things about this setting... It seems to never get brighter when you first set it up. VERY SLOW ramp-up and down. It actually takes an hour or so to ramp up to 100% intensity. Nice, really... but I thought it wasn't doing anything at first. And the same to ramp down. The only issue I may have with this setting is if I get too much green algae. That's my sign in my planted aquarium that there's too much light. There's no control on this setting other than time-shifting. I'd like to be able to set an upper limit on intensity.So, depending on my needs for the plants and balancing the algae issue, I may end up using the timer versus the 24/7 setting. That jury is still out.Excellent product! Now, if only someone made one exactly like this one only with a USB port and completely programmable! ::hint! hint!::***********After a week or so of using this light, I've settled on the timer function as my default. I set the timer to start at 9AM and go to 9PM. Because I am always up long before 9AM, the timer mode allows me to turn on the light earlier without disturbing the OFF time of 9PM. Also, before 9PM, I can step down the light so that when I turn it on at 7AM or whatever, it's pretty dim, and then I can go from there until feeding time an hour after lights on. More manual, but I'm a control freak, which I think you have to be a bit to keep fishy friends.

This light is GREAT!! I set the day/night cycle, and the light did the rest. It slowly transitions throughout the day, and the crabs respond. Highly recommend!!

Wonderful tank light. The dawn to dusk setting is neat to watch change through the day and the fish seem more relaxed. They seem more calm with the gradual increase in lighting rather than the “rude awakening” by a light that turns on fully as my room is very dark and the full force brightness by my previous light seemed to wake them with a shock!Highly recommend this light for that setting. Also, setup was simple and the wire legs seem sturdy and were easily fit to my 110 gallon tank.

So far this light has worked well on my 75 gallon planted aquarium. The only issue is with the timer that has to be reset each time the power goes out. And the only way to set it right it to turn the timer on as the sun comes up to get the on time right.

I purchased the 48-54 inch model and it fits perfectly over a 55-gallon long tank, a common standard the aquarium industry. I highly recommend this, especially if you are currently using the legacy fluorescent bulbs over the top of your aquarium now.With full-spectrum LED lighting, the colors in my tank now appears much more vibrant over the previous fluorescent setup I employed previously.I use the 24/7 lighting option, which manages the lighting from dim and red light at the crack of dawn, until the light becomes brighter and more vibrant until the peak brightness of midday. Then, late in the afternoon the lighting ramps back down again until post-sunset, when the light becomes blue for an hour or two before switching off again at night. This really is nice and wasn't possible in a single lighting system until full-spectrum LEDs became the standard.This product isn't perfect. The lack of custom time setting options, a digital clock or color wheel found in some of the more expensive LED products make the configuration options somewhat more limited, non-intuitive and difficult, without the use of the instruction manual.Still, I think there is tremendous value here for the money, especially if you're looking to dip your toes into the LED lighting world for your aquarium. I love it and won't go back.

Fits my 29 gal.tank. looks real good on the lighting, as well the functions that came with it

I’ve put one of these on all 3 of my planted tanks.The 24/7 mode is what I leave them on and it works great. Don’t need to worry about the lights being on too long/powerful.Starts the day with a deep orange sunrise then works its way to brighter and brighter, then tapers down to deep blue by the end of the night.

This is a really good light for plants ready for a while already like the fact that it has the 24/7 light feature and it is bright multiple colors